The company has been in decline for a number of years. That should partly be blamed on the product but dig deeper and identify the other constant.
With a last in first out policy, recent hires who have not created the negative impact on existing clients have had very little time to positively impact growth. The issue therefore has to be those long established sales people who have been the one constant through a period of decline. You don't need a data scientist with hours worth of expended effort analysing data to outline the issue.
Incapable Sales people who do not have the intellect firstly identify the risk on existing accounts and secondly outline a plan to mitigate that risk. The only objective has been to grab the low hanging fruits and then move onto the next tree whilst others are left with the managing accounts where it's simply too late strategise a recovery plan. They have made hay whilst the sun has been shining. Others who trying to fix this mess, have been like a staffordshire terrier barking up the wrong tree where there is no bait to be found.
Frankly, it's clear it is now too late to regain any momentum, and like some areas of Norway, Teradata is in a period of darkness as night time is firmly set in.