Proprietary software???

My work bought two used 2012 International Pro Star+'s that had gone through the Int. Diamond Renewal program. Owner got them mainly cuz of a 200k engine warranty. One day cab, one sleeper both 250 thousand miles. The sleeper truck has been a problem since pretty much day one. Constant regen, 6 times in the first 1500 miles and been getting worse no matter what the service shop says they have done. Not using this to rag on International, i really like the day cab and since its been going on since early in the ownership the dealer is working with us for the most part. When you have a bad truck it's never enough though. One of the things in all this we find out International has proprietary software on the Maxxforce engines so only a International shop can work on them. How common is this for truck manufacturers these days? Wondering this because it sure seems like we are heading down the replacement road already and I hear so much grumbling about all newer low emission trucks no matter the brand. Prior to these trucks our newest was a 2008.