I'll throw in my two cents on this.
Firstly, a society is only as good as the people in it. All political parties are the same, good or bad depends on many factors, many of which are beyond their doing or control. If the citizens are cohesive, disciplined and hardworking, it will progress with a minimum government involvement. If the citizens are rebellious, polarised, disunited and irresponsible, the society will fail despite how good the government may be. I believe that Singapore grew well since independence because her people are basicaly not trouble-makers. Trade flourished because of regional peace (this, gotta thank Suharto), industry grew because of a peaceful society too, of course being favored by the powers of the day helped. If there was more freedom to the arts, creativity may have grown too, but the population and country (and hence market) is small.
All through this period, all the credit has gone to the leaders - without any talk on the sacrifice and efforts of the people - I wonder why? And because of this, the picture painted is that all this progress was achieved due to the leadership! All?
Well, the WP has been the underdog all this time, but now, its harder for the top dog to bear its teeth. No, the WP is not the machinery the PAP has evolved into, but if there are any ill-feelings for the PAP, it is natural and can't be avoided.
Cheers!