I don't quite understand your argument.
Assuming there is (1) a distinct linear trend between block reward halvings and (2) these linear trends continue to get steeper after each halving, then the long-term trend will be exponential, not linear.
You could chop any exponential bubble chart into small pieces and draw a straight line through each of them. The complete chart will still be exponential. When talking of a long-term trend you should draw your trend lines on a single long-term chart. Then you'll notice that it doesn't look linear at all.
I had not thought of that. The linear rate will increase at each halving. But I think most people see an exponential increase of demand while I think over time it will be linear with small bursts as major developments take place.
Over time the affect of inflation will level out when block reward is replaced more by transaction fees as the reward for finding a block.