I don't think there is anything wrong with spurs, as long as they are only used when necessary and the rider is experienced enough to use them without hurting the horse. I ride in the smallest, most dull nubbed ones I could find, and they work great for a little added encouragement with my draft cross because he is a bit more on the lazy side. Remember that the more you kick the horse, the duller they become. You becoming a 'nagging mother' so to speak, and the horse will become less and less sensitive to your aids. You have to be really black and white.
What I do is use my own version of the natural horsemanship pressure, cluck, spank (ask/tell/demand) method. I ask with a soft pressure from my calves and heels. If my horse doesn't respond, I cluck and dig my heels in a bit to make him feel a bit more uncomfortable for ignoring me, and the short spurs help with this as well. If he still ignores me, then I use a soft tap of the dressage whip behind my leg (but remember to use it WITH leg and not by itself). In the beginning, I had to escalate the pressure of the dressage whip as well - DO NOT STOP putting the pressure on until your horse tries. This is so, so important. If they pin their ears, make a growly face, swish their tail, etc. and you back off, they learn that displaying that kind of behaviour will make you leave them alone and they'll keep trying to get away with it even more. They learn at the point you stop what you're doing, not when you start whatever you're doing. A little bit of resistance in the beginning is normal. I experienced this with my gelding - he'd pin his ears for a second, swish his tail, and then irritatingly move into a trot. As SOON as the horse tries, you have to back off all pressure. They learn from release of pressure (aka comfort). You can also use the actual method without my modifications - you ask with leg pressure, then cluck (vocal command) if they don't respond, and then spank them on the bum with your hand until they move out. I modified it because I don't want my horse to rely on voice commands and me spanking him because this wouldn't really be permitted if I were to show him in dressage or something, but it's the owner's preference in the end.
The horse eventually learns the steps in your process, and comes to understand that if they ignore you, the steps will escalate in pressure and make them feel more uncomfortable for ignoring you. Eventually, they will begin to respond from your slightest cue. When I first got my gelding, his trainer was kicking him repeatedly and using the crop a couple times on his shoulder just to move him into a trot. Now he responds to my leg cues without spurs or whip or anything and his resistant behaviour has left completely. He goes willingly into the trot with his ears perked and I don't have to constantly be kicking him to keep him in the trot. I still wear my spurs sometimes for enforcing if I have to, but I haven't had to use them hardly at all. Most importantly, start with the smallest amount of pressure you can - your horse will never become any more sensitive than the first pressure you apply - if that is a hard kick, that's as sensitive as your horse will become and it will take a long time to correct it. If the first pressure you use is a few ounces against their side, with patience and time, they will eventually come to respond to that. Remember to make it as easy as possible, but be as firm as necessary. You can always escalate the pressure, but you can never diminish it if you start at high intensity.
Oh, and once your horse becomes more sensitive and responsive to your aids as far as moving them into a trot, do LOTS and LOTS of transitions. From your message, I'm guessing this horse is quite green and young? So is my guy, and the other thing to consider with babies or green horses is that they don't understand the correlation between pressure and moving forward. This is totally normal in the beginnings of training, so don't think it's a weird or 'problem' behaviour. They just don't understand. You need to work with them and give them time to understand, be very black and white, and give them TONS of reward when they do the requested action.
Hope this helped. :]