It's not clear from your post if your are talking about using the computers in the business center or your own system. The business center PCs appear to be provided by local suppliers and they have all been set up differently. Sometimes they appear to be discarded systems put in to satisfy being able to check the box that they have PCs.

I travel with my own laptop and have cellular broadband for exactly that reason. Some properties feel it is appropriate to throttle/block traffic for whatever reason. If their's works, great, if not I'm still good to go.

Many years ago I remember getting to my room to find a letter saying since so many people are using computers in their rooms they could not guarantee being able to get an outside line (back in the modem days) between certain hours of the day. And that was for voice calls too! Heaven help them if there was an emergency.

Since no one can predict what traffic will happen at any given time, I find it tough to expect fast network traffic every minute of the day. Just like offices don't provide trunk lines for every phone on their PBX, hotels don't equip their properties with bandwidth for worst-case usage.