That is what most people think including me. However what are your friends with the sim diploma/degree doing now?
If they are doing well then maybe it is not a bad choice going for other degree. Basically how I rank "doing well" is from pay...i've been researching degree holder pay since I got my smu appeal rejected (beside for ntu appeal, still waiting!)
If someone with private degree with few year/no experience, a pay of around 3k would be "successful" to my standards la...
I read somewhere that unisim is the 4th placed uni in SG (not sure now after the introduction of SUTD and SIT)
The other route is to get working experience then apply again which is what i'm planning now. Aiming for next year ntu/smu with near 2 years relevant IT working experience and if i'm in, i'll be 31 if I get my degree