You won't attract people to the HML if it remains - slow - unreliable - not enough seats and more convenient to take the car. So investment is needed. Four coach HST's seemed to be an improvement, but despite their potentially superior performance and the spending of money to improve reliability, the proposed faster timetable has not been launched, and HST's frequently swapped out with smaller DMU's. The DMU's can run at higher speeds in places. There's no news on any track work changes to take advantage of the HST's better acceleration and ability to hold higher speeds on the climbs.
We are talking about long term investment here. LAst time I went to Inverness I saw loads of new houses and apartments being built. People are being attracted to live in the Highlands. These people will want to travel for work and pleasure. They will have a choice. Travel on a 2-hourly (at times) non-improving rail service or drive their cars down an improving A9 and get onto the public transport network from places such as Perth/ Stirling, Glasgow or Edinburgh where frequency and journey times are as good as driving.