This is a problem when you get non tech people running a tech company (can they be considered one?). They perception and vision is totally different. With profits in mind they'll do just enough, which in a way is not wrong since it's a business after all but problem is the colluding between the 3 companies to bring down the data cap. If their reason was cos people are hogging the bandwidth with video streaming, which i think WAS their reason then throttle it for people with aggressive video downloads. Problem is now 4G speed getting faster but data cap so low, it's as good as not having it.
I feel that is a rather simplistic view of the situation. The unfortunately reality is that wireless spectrum is always limited - there is only one radio spectrum to be shared by everyone without interference, unlike wireline fibre optics where you can have the entire spectrum all to yourself on each strand of fibre. So the faster the network, the more the data each user pumps into it, the less bandwidth is available for everyone else. A simple analogy is that the wireless spectrum is like a cake. If everyone eats faster, the cake will disappear faster. If the telcos allow unlimited plans, their networks will simply be overloaded, regardless of how many cells they put up, because there is just not enough spectrum for them to handle the load without interference.
What you said about the profit-orientation of the telcos is true. They are fully-invested in LTE, which allows them to optimize their investment in the spectrum they purchased from IDA. If they truly care about customers, they should continue to invest in the less efficient 3G networks where speeds are slower, and hence allow more users to share the same network with a much lower risk of interference. That was why 3G plans used to offer unlimited bandwidth. Unfortunately, many telcos are repurposing their 3G spectrum for LTE use.
Capping LTE usage is also a strategy used by telcos against the over-the-top voice service operators such as Skype and Whatsapp. Since they are not allowed to throttle these services due to net neutrality regulations, they simply make it more expensive for users to use them.
So instead of asking for unlimited 4G plans, what we should do as consumers is to press IDA to require telcos to continue to offer lower speed plans based on 3G with unlimited data access. An alternative is to allow 4G speeds for the 1st 2Gb of data, and throttle that down to 3G speeds for any data in excess. That would be a pseudo-unlimited plan.