what used to be once in 5 year exercise is now big money spinner and grown into an industry. so its natural to have elections of all kinds on monthly basis so that it keeps the industry alive perpetually.
Knowing the politicians dedication for development of India Vs Their own financial development, Public of India must keep final control with us and public of India have only Voting Right to stop anarchy of politicians. Parliament is not directly accountable for development of states , so there is no evident relation that state and Parliament elections needed at one time. It is problem of only national parties who wish to save their eand then wish to have complete control on country. How it will ensure that power will be not misused by ruling party if they are present everywhere and there is no strong opposition party available to ask right questions. Present system of elections at different time compels politicians to be on their toe and perform otherwise they get taste of defeat as a signal of poor performance, present system is like continuous evaluation process for politicians performance by public and it is helping in controlling corruption and political anarchy in country.
One way out would be to have some state elections with the parliamentary electons, and the rest state elections at half-term, say, 2 1/2 years after the parliamentary elections. While this will substantially address the concerns of repetitive expenditures and effect of frequent election-mode on governance, it will also leave a window to guage publc mood on policies at half term